The US Federal Emergency Management Agency (FEMA) has attracted its own protest group, as further measures to phase out National Flood Insurance Program subsidies began last week.

Moves to adjust premiums to reflect risk have led to substantial rises in areas of New York, New Jersey, Louisiana and Florida, giving rise to the Stop FEMA Now movement.

The group held protests after FEMA released new flood maps for New York and New Jersey, where shoreline homes face five-fold premium increases.

Nationally, business property owners with subsidised premiums will now pay 25% more each year until their rates reflect the full risk in four years.

Rates for non-primary residences have already started rising, while owners of homes with severe repetitive loss will also be affected from this month.

Many other property owners, including those without flood subsidies but who are affected by updated flood mapping, will start to pay full risk rates from next year.